(Trochilidae; Ϯ Blue-throated Sylph A. kingii) Gr. αγλαια aglaia  splendour, beauty  < αγλαος aglaos  splendid; κερκος kerkos  tail; "Lesbia Lesson 1833 (Troch. Index Gen., p. XVII, 1833) contained three species, sapho, nuna, and kingii. Gray three times designated Trochilus forficatus Linnaeus as type species under the mistaken notion that kingii was a synonym, but since forficatus was not among the original species, these designations  are invalid. Salvin (Cat. Birds. Brit. Mus., 16, p. 146, 1892) seems to have been the first to comply with modern requirements when he designated nuna as the type of Lesbia. Incidentally this requires the use of Lesbia for the genus known recently as Psalidoprymna, but it leaves the present genus without a name. To supply the deficiency I propose the name Aglaiocercus with Ornismya kingii Lesson as type species." (J. T. Zimmer 1930).
Synon. Cyanolesbia.

Search for more names on the Key to Scientific Names in Ornithology by James A. Jobling.
Recommended citation
Jobling, J. A. (2019). Key to Scientific Names in Ornithology. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2019). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 20 January 2019).